Loss of Gen

by Phill Hooker in 912iS Technical Questions 9 years ago

If we lose a generator(rare) in the 912is engine there is no warning to the pilot. Obviously if we lose both we will find out very soon. Why do Rotax not provide a warning system, is it a design fault? most aircraft i have flown will always indicate somehow that an alternator or generator has failed

Re: Loss of Gen

by Rob Seaton » 9 years ago

Rob Seaton

3 1.32k 251

I did not know this so just tried some tests:
Start up test:
Disconnect gen 1 (16A) and engine starts but both lane light flash rapidly.
Disconnect gen 2 (30A0 and engine starts but as soon as the "startpower" switch is released the engine quits.
so you really would not be able to take off with a gen failure (unless you intentionally tricked it by using the back-up switch)

Ground run tests simulating in-flight (3000rpm)
gen 1 disconnected: engine keeps running, no lane lamp, discharge lamp on volt/ammeter comes on (-7.8A). back-up switch on, charge goes to 3.5A
gen 1 reconnected
gen 2 disconnected: Engine keeps running, no lane lamps, volt/amp shows discharge -1,2A. turn on back-up swt and charge goes to 7.0A
gen 2 reconnected.
Both gens unplugged at same time: engine stops.
both plugged back in, engine re-started: 3000rpm
Unplug one at a time, notice the volt/amp discharge and turn on the back-up swt. unplug the other and engine keeps running with a -7A discharge (only GPS, comm & xpdr operating)
So it looks like you need to watch the ammeter (it is a requirement in the installation manual).

I have inquired for more information on this situation.
Can admin move this to 912iS forum?

Report
Re: Loss of Gen

by Phill Hooker » 9 years ago

Phill Hooker

7 17 0

thanks mate

Report
Re: Loss of Gen

by Richard Boslaugh » 9 years ago

Richard Boslaugh

9 122 84

I guess most of what a builder/owner gets in the area of engine alarms depends on what type instrumentation has been installed in the a/c.

With the Advanced 5600 EFIS for generator/voltage alarms I get; red alarm flags and audio alarms for each generator. Also have #2 generator voltage and current load. Because the engine instrumentation data is in the CAN buss format it seems that all a/c will have some type of electronic display which will present engine data in some format.

Also the 5600 has a flight data down load function which records 49 flight and engine parameters at 5 second intervals. The down load
can be displayed with excel or word. I am not familiar with other manufactures of EFIS systems but assume most have similar features.

Thank you said by: Phill Hooker

Report

You do not have permissions to reply to this topic.

Title	Category	Replies
Generator not charging	912 / 914 Technical Questions	1
912 ULS intermittent Vibration - no power loss	912 / 914 Technical Questions	5
912 UlS lässt sich nicht über das Zündschloss ausschalten	912 / 914 Technical Questions	6
Intermittent power loss	912 / 914 Technical Questions	4
914 very intermittent partial power loss	912 / 914 Technical Questions	5

Loss of Gen

Recent Videos

Safety First!

Prize Giveaway!

Log In/Out

Login